Element has landed on calling these "recovery keys" and we should do the
same. Since these have had various names throughout the years and in
previous versions of NeoChat, they are still mentioned.
I also renamed "Secret Backup" to "Key Storage" which is also Element
terminology.
The devices entry gone (not even Element has this) and so is the logout
action. The Switch account menu item is moved to the bottom so its
easier to access by mouse. The "Open Secret Backup" is moved under
Security settings where it lives next to the other crypto-related
settings.
